To properly dump your tanks, Paul recommends the following. Keep both the grey and black dump valve closed until one or both tanks need to be emptied. Connect your sewage hose to the dump fitting on your camper. The other end of the sewage hose goes into the dump station waste tank.
The next steps need to be done in the following order. First, open and dump the black tank. Once it has stopped running, leave the black valve open. Second, pull the grey tank valve open. This will flush out the plumbing and sewage hose washing the residual human waste and tissue out into the dump station tank. When they grey tank has stopped running, don’t forget to close both the black and grey tank valves. And third, now that you have freshly emptied tanks, it is a good time to pour holding chemical into the toilet/black water tank.
Some truck campers come equipped with black tank flush connections. These connections allow you to flush out your black tank with non-potable water as found at most RV dumps. To flush your black tank using a black tank flush connection, hook-up a non-potable water hose to the black tank flush connection, turn on the non-potable water, and let the black tank drain into a RV dump station. This flushing process helps to clean out your entire holding tank and is generally very effective. Just make sure that you never use your fresh water hose to flush your black tank.
If your camper does not have a black tank flush connection, you can still effectively clean out your black tank using a tool called a toilet wand. A toilet wand is a long tube that connects to a hose and extends down into your black tank through your toilet. Once the toilet wand is in the black tank, it shoots water into the black tank to rinse off the sides of the tank and the tank sensors. Again, do not use your sanitized fresh water hose for this operation.
Some truck camper owners even dump fresh water and ice cubes down their toilets and into their black holding tanks. Then they drive down the road to clean out their black tanks. Once the ice cubes melt, the resulting water will safely pass through your camper dump valve.
Paul added that you should never use household toilet cleaners as RV toilets are made from plastic, not porcelain. He suggested a Thetford product called Aqua-Clean.
Holding Tank Sensors
According to Paul, the sensors used on RV holding tanks are not an exact science. Many things can affect sensor readings including how level your camper is. For the black tank, human waste and toilet tissue can accumulate on the sensor and give a false reading.
Above: We observed holding tanks getting installed at Lance Campers last summer
This is why it’s important to regularly clean your black tank with a black tank flush connection or toilet wand.
If you just dumped your tanks but the black tank is still reading full, it’s time to clean your black tank. For this cleaning, Thetford has an excellent product called Level Gauge Cleaner. Other manufacturers produce similar products.
As we’re learning through our Ask The Expert series, there is a short but critical list of truck camper components and systems that need to be cared for and maintained if a camper is to be kept in good working condition. With this article, we add holding tanks to our list that now includes electrical systems, camper jacks, propane systems, cassette toilets, and camper seals.
The good news is that camper maintenance does not need to be difficult. Follow Paul’s expert advice and your fresh, grey, and black tanks will be working for many years to come. Thank you, Paul!